Humic acid lignite coal based liquid fertilizer

ABSTRACT

The disclosed invention relates to novel fertilizing compounds comprising a combination of inorganic fertilizers and humic compounds. The combination produces a marked benefit over either type of substance individually, and also over previously known combinations of organic and inorganic fertilizers. The invention also relates to a method of production of such compounds.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application of U.S. Ser. No. 12/356,163filed Jan. 20, 2009, which is a Continuation application of U.S. Ser.No. 11/940,375 filed Nov. 15, 2007 (abandoned), herein incorporated byreference in their entirety.

FIELD OF THE INVENTION

The present invention relates to the field of agronomy, moreparticularly to agricultural fertilizing compounds.

BACKGROUND OF THE INVENTION

Higher plants are autotrophic organisms that can synthesize all of theirmolecular components from inorganic nutrients obtained from the localenvironment. Nitrogen is a key element in many compounds present inplant cells. It is found in the nucleoside phosphates and amino acidsthat form the building blocks of nucleic acids and proteins,respectively. Availability of nitrogen for crop plants is an importantlimiting factor in agricultural production, and the importance ofnitrogen is demonstrated by the fact that only oxygen, carbon, andhydrogen are more abundant in higher plant cells. Nitrogen present inthe form of ammonia or nitrate is readily absorbed and assimilated byhigher plants.

Because of the dependence of plants upon nitrogen, farmers frequentlyinclude nitrogen in their fertilization efforts of their fields in aneffort to increase yield. This practice may be traced back to the1800's, when it was discovered that when external sources of watersoluble forms of nitrogen (along with phosphorus and potassium) providedto plants, yield increased. These fertilizers are typically applied tothe soil, but can also be applied to plant leaves directly.

Nitrogen fertilizers are often synthesized using the Haber-Boschprocess, which results in the production of ammonia. The ammonia is theneither applied to the soil or used to produce other nitrogen compounds,such as ammonium nitrate or urea. These compounds are then applied tocrop fields in order to increase yield in areas where the nitrogencontent of the soil is low.

Unfortunately, the production and use of nitrogen fertilizers hassignificant drawbacks. For example, it is currently estimated thatammonia production accounts for 5% of the global consumption of naturalgas. With the increase of natural gas prices over the course of the pastdecade, the cost of producing ammonia has correspondingly increased. Inaddition, overuse of nitrogen fertilizer can lead to pest problems byincreasing the birth rate, longevity, and overall fitness of certaincrop pests. Also, there are substantial concerns regarding fertilizerrunoff, which can add undesirable compounds to rivers, streams, andground water supplies.

It would therefore be desirable to minimize the application of inorganicfertilizers to field crops while finding a way that the increased yieldthose fertilizers typically provide may still be obtained.

Another source of plant nutrition historically has been humus, which iscommonly referred to as organic matter. Humus is sometimes referred tosimply mean mature compost, and is often thought to make up thestructural component of soil. Most humic compounds are produced via thecomposting process, but others are available from other sources, such aspeat moss, manure, and coal.

Such humic compounds have been used as soil enhancers or fertilizers forquite some time, but the greater benefit seen by artificial applicationof inorganic compounds such as nitrogen described above have proven morebeneficial in most farming applications, or at least more costeffective.

Because of this perceived greater benefit to the application ofinorganic nitrogen and other compounds (such as potassium andphosphorus), the level of humic compounds present in the soil hasprogressively declined with the increase in commercial farming and thelack of replenishment. As a result, greater amounts of inorganicfertilizers are needed in order to achieve the same or similarfertilizing effect, as the soil in many instances is less able to retainthe chemical fertilizers applied to it, and as a result plants are lessable to utilize such fertilizers unless they are applied in greaterquantities. This shift in soil dynamics over the course of time hascontributed to the negative impacts of chemical fertilizers noted above,as with increased application of such fertilizers, there is acorresponding increase in the potential for occurrence of the negativeside effects of such fertilizers.

While these problems have been recently identified, a suitable solutionhas yet to be found. Combining various humic substances with variousinorganic fertilizing materials, such as nitrogen, phosphorus, andpotassium, does result in a somewhat improved fertilizing effect.However, previously used substances have not yet achieved desiredresults based on the vast numbers of alternative sources of both humiccompounds and inorganic complements, as well as the vast number ofpossible differences in composition and method of preparation. As aresult, there has been a need for a compound that is able to deliverboth for the benefits of humic compounds and inorganic fertilizers witha high degree of fertilizing efficacy.

BRIEF SUMMARY OF THE INVENTION

The present invention therefore relates to a fertilizer compound thatreduces or eliminates one or more of the drawbacks of traditionalinorganic fertilization techniques. The present invention also relatesto a fertilizer compound that produces a synergistic affect betweeninorganic fertilizers and humic compounds. The present invention furtherrelates to a method for producing such a fertilizer compound. Additionaldetails regarding preferred embodiments of the present invention willbecome evident from the further description provided.

DETAILED DESCRIPTION

In accordance with the claims, the inventors herein disclose a novelfertilizer compound that reduces the necessity of traditional nitrogenand other inorganic fertilizations. Embodiments of the invention alsocan contribute to soil quality, water retention, nitrogen retention, andimproved aeration.

In another aspect, a method of production of a novel fertilizer compoundis disclosed by which one or more of the above-described benefits may beobtained. Further detail of the invention will be evident in theadditional description herein provided.

Humic Fertilizer Composition

The claimed fertilizer composition has at least four predominantcomponents. These include nitrogen, phosphoric acid, potassium hydroxide(potash), and an organic component. Preferably, the organic component iseither lignite or leonardite. Most preferably, the organic component islignite. Lignite may be obtained from any appropriate source, such ascoal mines or their distributors.

The nitrogen in the composition may be obtained from any acceptablesource, such as fertilizer dealers, farm cooperatives, and the like.

The phosphoric acid is preferably fertilizer grade phosphoric acid,rather than the more highly purified food grade phosphoric acid that isalso available. It is believed that this improves the properties of thefertilizer as the fertilizer grade phosphoric acid contains additionalimpurities which also are sometimes present in soil and utilized byplants in small amounts. The phosphoric acid may be obtained from manychemical companies, such as Hydrite Chemical, or can be produced byvarious methods, such as that disclosed in U.S. Pat. No. 4,462,972. Thepotassium hydroxide, or potash, may also be obtained from any acceptablesource, such as from any number of chemical companies.

The composition herein claimed is preferably a liquid fertilizer. It maycontain between about 25% and about 63% nitrogen, between about 10% andabout 50% lignite, between about 5% and about 30% phosphoric acid,between about 5% and about 10% potassium hydroxide (potash), and theremainder of the composition water. Preferably, the nitrogen makes upbetween about 30% to about 55% of the composition, and most preferablybetween about 40% and about 50% of the composition. These percentages ofnitrogen are based upon a 28% liquid solution, and therefore thesepercentages would change if a solution with a different concentration isutilized. For example, if a 32% liquid solution is used, the fertilizermay contain between about 20% and about 60% nitrogen, preferably betweenabout 25% and about 48%, and most preferably between about 40% and about46%.

Preferably, the lignite makes up between about 15% and about 25% of thecomposition, and most preferably between about 18% and about 22% of thecomposition. Also, the lignite is preferably between 50 mesh size and250 mesh size, and most preferably the lignite is 200 mesh size.

The phosphoric acid preferably makes up between about 8% and about 20%of the composition, and most preferably between about 12% and about 15%of the composition. These percentages are based upon a 75% phosphoricacid solution, and as a result the percentages will change if adifferent concentration solution is used. Also, the phosphoric acid ispreferably fertilizer grade. Similarly, the potash preferably makes upbetween about 6% and about 9% of the composition, and most preferablybetween about 7% and about 9% of the composition. These percentages arebased upon a 45% solution of potash, and as a result the relevantamounts will change if a different concentration is used. The potash maybe obtained from any acceptable source, for example from a commercialchemical company such as Hydrite Chemical in Waterloo, Iowa.

This composition is applied to the target field preferably at a rate ofabout one-third gallon per acre. The compound is sprayed much like anyother liquid fertilizer, although for best results, a 20 mesh screenshould be used in order to minimize clogging of most standard sprayapplicators.

Applying the disclosed compound provides a substantially improvedfertilizing effect over and above that expected with other fertilizingcompounds, such as nitrogen or other inorganic compounds alone, organicfertilizers alone, or even pre-existing combinations of inorganic ororganic compositions in fertilizer compounds.

In addition, application of the disclosed compound allows the soil toretain water and other nutrients, which provides at least two beneficialeffects. First, it minimizes the likelihood of runoff of fertilizer inareas where the fertilizer is not desired, such as rivers, streams, orgroundwater, thereby reducing the potential for negative environmentalimpact. Also, because various soil nutrients are retained at a higherrate, a lower amount of inorganic fertilizers are required to achievethe same fertilizing effect with future applications of either thisfertilizing compound or other inorganic, or combination fertilizingcompounds. As a result, the compound herein described provides anunexpectedly high level of benefit to both soil quality and increasedfertilizing efficiency, over and above that previously achieved withsimilar fertilizing compounds.

Method of Production

In order to produce the above-described compound, it is preferable touse a stainless steel horizontal mixing tank with a mixer installed oneach end. First, the nitrogen solution is added to the tank, followed bythe lignite. While these ingredients may be added in reverse order,adding the nitrogen first is preferable as the lignite is suspended inthe mixture more quickly. The nitrogen and lignite mixture is then mixedat high speed for eight minutes.

Then the phosphoric acid is added to the mixture. This also assists withsuspension of the composition into a liquid. During this mixing phase,the compound may produce visible vapor. The compound should be mixedabout ten to twelve minutes.

The water is then added, and the composition is mixed for a further tenminutes. Adding the water at this stage is preferable because it iseasier to keep the lignite suspended in the mixture when added after thenitrogen and phosphoric acid. Finally, the potash is added. For safetyreasons, it is preferable to add the potash slowly, because if it isadded too fast to the mixture an explosive reaction may occur. Addingthe potash also increases heat of the compound, and causes a strong odorto be emitted. The potash neutralizes the pH of the mixture, balancingout the phosphoric acid. Once the potash is added, the compound shouldbe mixed for approximately twenty minutes.

Once the product is done with the mixing steps, it is then ready forfiltration. The product is preferably slowly added to a filter screen,and preferably filtered by gravity flow. The preferred filter size is abetween 20 and 70 mesh.

A majority of the product will pass through the filter, but a smallamount will not pass through. The product that does not pass throughshould be discarded.

Once the compound has been filtered, it may be appropriately packagedfor distribution to field sites. When packaging, it is preferable to adda small amount of defoaming agent before filling so that foam isminimized and containers do not have to be refilled after the foamproduced in the filling process settles out. The containers may then besealed and stored for shipment for application.

This method of production is preferable to previous methods used inseveral ways. For example, by adding the water later in the process, thelignite stays suspended more completely in the solution, therebyreducing clumping in the final product, which can cause clogging in theequipment used to spray the compound onto fields. Further, the use ofgravity flow through the filter as opposed to a pumping procedureresults in a superior product, because changes to the final structureoccur when the product is forced through the screen as opposed toletting it naturally proliferate through the screen.

It should be understood that the forgoing invention has been describedin the context of preferred embodiments, and that modifications apparentto one of ordinary skill in the art are intended to be encompassedwithin the invention. Further, the scope of the claimed invention shouldonly be limited by the appended claims, not the scope of the specificexamples provided herein.

What is claimed is:
 1. A method of producing a fertilizer composition,comprising: (a) preparing a mixture consisting essentially of liquidnitrogen and lignite; (b) adding phosphoric acid to the mixture; (c)mixing the phosphoric acid with the mixture; (d) adding water to themixture and phosphoric acid to form a solution; (e) mixing the waterwith the solution; (f) adding potash to the solution; (g) mixing thepotash into the solution; (h) filtering the solution, wherein filteringis performed by gravity filtration; and (i) placing the solution into acontainer.
 2. The method of claim 1 wherein the mixture mixed for about8 minutes.
 3. The method of claim 1 wherein the phosphoric acid andmixture are mixed for between about 10 minutes and about 12 minutes. 4.The method of claim 1 wherein the water, mixture and phosphoric acid aremixed for about 10 minutes.
 5. The method of claim 1 wherein the potashand solution are mixed for about 20 minutes.
 6. The method of claim 1wherein the phosphoric acid comprises fertilizer grade phosphoric acid.7. The method of claim 1 wherein the solution is filtered through afilter screen.
 8. The method of claim 7 wherein the filter screen is a200 mesh size.
 9. The method of claim 1 further comprising adding adefoaming agent.